Typewriter cabinet



F 1952 c. B. LUNDSTROM TYPEWRITER CABINET Filed Oct. 27, 1947 2SHEETS-SHEET 2 Fis.4-

INVENTOR. Carl. Brgno'lf Lundscrom Q BY (dim ATTORNEYS Patented Feb. 12,1952 TYPEWRITER CABINET Carl Brynolf Lundstrom, Little Falls, N. Y.

Application October 27, 1947, Serial No. 782,331

2 Claims.

This invention relates to cabinets of the disappearing instrument typeand particularly to typewriter desks of that type in which a platform isguided in one continuous movement, and by a parallel motion linkagepivoted to the desk, from an active position in which it projects froman opening in the front of the desk to a storage position in which it iswholly within the desk.

The development of typewriter-desk equipment for use by clerical forcesof large corporations has two conflicting trends. Conservation of floorspace dictates the use of desks of minimum dimensions, whereas the needfor filling out rather large forms frequently requires the use ofwide-carriage typewriters.

The object of the invention is to afford a mechanism of the typementioned which will be simple and which will house a wide-carriagetypewriter in a desk which, measured from front to back, is small.Rather complicated mechanisms to meet this condition have beenmanufactured. One well known device of this type has a carriage on whichthe platform is rolled out to the front of the desk, and then elevatedby the operation of a parallel-motion linkage. These devices areexpensive and unduly complicated. The present invention permits the useof a parallel-motion linkage without any carriage.

How effective the invention is, may be gauged by the fact that, whereasin all prior art devices known to me and involving the use of a linkagewithout a carriage the maximum width of typewriter which can beaccommodated in a 30-inch desk is the so-called 11 inch size, whereas a30- inch desk constructed according to the invention will accept amachine having a 14 inch carriage. This comparison is based on thedimensions of the so-called noiseless type of machine manufactured bythe Underwood Typewriter Company, in which the overall width of the 11inch size machine is 16% inches and the overall width of the 14 inchmachine is 20%, inches.

The result is accomplished by pivoting the swinging arms of theparallel-motion linkage to the desk in a horizontal plane which isspaced below the top of the desk a distance approximately equal to theheight of the platen axis of the typewriter above the machine-supportingsurface.

Another feature of the invention is the use of L-shaped levers whoseform will be described in some detail.

The effect of the stated location of the supporting fulcra is to causethe guided platform to swing outward in the initial part of its motionfrom the extended position toward the housed position. In this way theplaten knob of the typewriter is caused to clear the front edge of thedesk without objectionably limiting the retreat of the platform into thecabinet during the latter portion of the housing motion.

The invention will now be described by reference to the accompanyingdrawings, in which Figure 1 is a sectional view through a desk showingthe platform in its projected or working position. The silhouette of thesupported typewriter is indicated by dotted lines. In this view theplatform is shown in elevation and only that parallel motion which is atthe far edge of the platform appears. It will be understood, of course,that in accordance with the usual practice there are identical linkagesat each side of the platform.

Figure 2 is a similar view showing the platform in an intermediateposition in its motion from projected to housed position. This positionis the one in which the platform has moved furthest outward asdemonstrated by the fact that the pivot connections between thesupporting levers in the platform are in a plane with the pivotconnection between the supporting levers and the desk.

Figure 3 is a similar view illustratin the lowest position reached bythe platform.

Figure 4 is a similar view showing the platform at the limit of itsinward motion.

In-the drawings, the desk comprises a sled base 6, a top 7 and a backwall 8, enclosing the instrument compartment 9 open at the front. Any ofthe well known closures for the open front of the space 9 might be used,but since this is not a feature of the invention, no closure isillustrated.

Supported in a horizontal position at each side of the space 9 is a barI I. This bar sustains one complete linkage but it will be understoodthat there are identical linkages similarly positioned and supported ateach side of the space 9. Hinged at l2 and IS on the bar II are twoL-shaped levers. l4 and IS. The swinging ends of these levers arepivoted to one edge of the platform at It and H, the platform beingindicated generally by the numeral I8.

50 To afford clearance for the drag link l9, which maintains parallelismof the levers l4 and I5, this link is connected to respective levers atthe pivot points 2| and 22 located in bowed ofisets formed in thelevers, as clearly shown in the 55 drawing.

A rock shaft 23 is journaled at its ends in bearings 24 supported at thetwo sides of the space 9, and carries near each end a two armed lever25, each lever being fixed to the rock shaft. One arm of a lever 25 isconnected to a counterbalancing spring 26 which acts in tension betweenthe lever and a support 21 fixed at the side of the cabinet. The otherend of the lever 25 is connected by a drag link 28 with a correspondinglever Id. The pivotal connections of the drag link are indicated at 29and 31.

The silhouette of the typewriter is indicated in dotted lines at T. Themachine is shown centered on the platform 18 with its carriage in midposition. The platen knob nearest the desk is indicated at K. It will beobserved that in Figure 1 the knob is directly above the desk top I.

In the initial downward motion, the platform has an outward component ofmotion and at the limit of such outward motion shown in Figure 2 theknob K is clear of the edge of the desk I. From the position of Figure 2the platform 18 sinks rapidly with an increasing inward component ofmotion until it arrives in the lowermost position indicated in Figure 3.The final inward motion has an increasing rising component until theplatform 18 reaches its fully housed position shown in Figure 4.

In the extreme outward position of Figure l the drag link l9 engages theupper face of the rear end of the platform and contributes to therigidity of the platform. The link also engages the top of the platformat the other limiting position and so serves again as a stop. (SeeFigure 4.) The rock shaft 23 constrains the parallel lever linkages atthe two sides of the platform to move strictly in unison.

In analyzing the motion of the linkage it is important to observe thatthe effective arm of lever 14 is the line l2-l6 and the effective arm oflever 15 is the line l3i'l. While the specific form of linkageillustrated in the drawings is preferred, the principle of the inventioncan be embodied in various different forms so that limitation to theillustrated embodiment is not implied.

It is probably unnecessary to explain that the spring 26 and theconnected lever 25 and link 28 have a toggle action and afford areversing bias. Thus the springs 26 serve to urge the platform to eitherof its two extreme positions.

What I claim is:

1. The combination of an open-front cabinet; an instrument-supportingplatform movable reversely between a first limiting position in whichthe platform projects horizontally near the top of the open front of thecabinet, and a second limiting position within and above the bottom ofthe cabinet; guiding mean for said platform comprising two parallellever linkages, each such linkage comprising two similar generally L-shaped levers, the arms of the L-shaped levers being unequal in length,the short arms of the two levers being hinged to the cabinet at spacedpoints lying in a horizontal plane at a height intermediate thepositions of the platform in said two limiting positions and the longarms of the two levers being hinged. at their ends to the platform atsimilarly spaced points. the parts being so arranged that in the firstnamed limiting position the long arm is at least approximatelyhorizontal and projects forward from the short arm and the short arm isat least approximately vertical and extends downward from the long armto its pivoted connection with the cabinet whereby the initial motion ofthe platform from said first limiting position is forward with anincreasing downward motion; drag links, one connected to the lever ofeach pair adjacent the junction of the two arms thereof, and so locatedas to engage the platform at each of said limiting positions and arrestmotion thereof; and means serving to retain the platform in itsrespective limiting positions.

2. The combination of an open-front cabinet; an instrument-supportingplatform movable reversely between a first limiting position in whichthe platform projects horizontally from and near the top of theopen-front of the cabinet, and a second limiting position within andabove the octtom of the cabinet; guiding means for said platformcomprisin two similar parallelmotion linkages, each linxage comprising apair of guiding iin rs serving to support a corresponding side edge or"the platform, and a drag link connecting the two links of a pair, saidguiding links each having three similarly spaced pivot connections,namely, a first pivot connecting the link with the cabinet, all saidfirst pivots lying in a horizontal plane intermediate said first andsecond limiting positions, a second pivot connecting each link with anedge of the platform, the pivots of a pair of links being similarlyspaced on the cabinet and on the platform, and a third pivot whose axisis parallel with the axes of the first and second pivots and is offsetfrom an imaginary plane passing through the axes of the first and secondpivots of one guide link, said third pivots connecting correspondingends of the drag links with the guiding links, said drag links beingpositioned between pairs of guiding links so as to engage said platformin each of said limiting positions and thus serve as limit stops, saidimaginary plane in said first limiting position extending forward andupward from the cabinet-supported pivots whereby the plati'crm is guidedto start moving from the first limiting position in a forward andincreasingly downward direction.

CARL BRYNOLF LUNDSTROM.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,565,248 Axen Dec. 15, 19252,322,648 Lundstrom June 22, 1943 FOREIGN PATENTS Number Country Date99,489 Switzerland Nov. 26, 1921 289,882 Germany July 10, 1915 743,390France Jan. 6, 1933

